1. The Field of the Invention
This invention relates to electrically heated clothing and, in particular, to a shoe with an internal warming mechanism.
2. Brief Statement of the Prior Art
Electrically heated clothing such as gloves, mittens, etc., have been suggested by prior investigators. Usually, these suggestions have contemplated using a battery pack as the electrical power source which is connected through thermostats and/or switches to an electric resistance heating coil located in a glove or mitten.
These suggestions in the prior art have not been successfully commercialized since the electrical power requirements for the applications are substantial, exceeding that which can be supplied from a battery pack of acceptable size and portability. Additionally, batteries are very inefficient at low temperatures.
Although the feet and toes are the most sensitive to chilling and frostbite, these applications are not readily adaptable for warming of feet since the battery packs required are too cumbersome to be carried on the feet or lower limbs of the wearer with the result that lengthy power supply conductors must be used between the battery pack and the electrical resistance wiring.
The bulk, and low efficiency of batteries in cold weather are significant detractants to the use of electrically heated clothing in active outdoor activities such as skiing, skating, hiking, etc.